JPS5955839A - Liquid absorbent for ethylene - Google Patents

Abstract

PURPOSE:To effect the absorption, separation, concentration and recovery of high concentration C2H4 useful as a raw material gas for chemical synthesis especially from various C2H4-containing gaseous sources, selectively and efficiently, by using a liquid absorbent for ethylene containing cuprous chloride, etc. CONSTITUTION:The novel liquid absorbent for C2H4 is prepared by adding trisdimethylaminophosphine oxide and an organic solvent, preferably one or more aromatic hydrocarbons such as toluene, xylene, etc. to cuprous chloride. The absorbent is effective to produce a high concentration C2H4 from exhaust gas containing C2H4 at a low concentration by absorption, separation and concentration. EFFECT:A high concentration C2H4 can be separated, concentrated, and recovered from the exhaust gas containing low concentration C2H4, stably in high yield, and the process is economical from the viewpoint of the installation cost as well as operation cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ethylene absorption liquid, and in particular, it relates to an ethylene absorption liquid containing ethylene (hereinafter referred to as C2H).
This relates to an ethylene absorption liquid for recovering C2114 from a locus source by contracting it.

[Chemistry] In Nijiang, the hydrocarbon-based thermal decomposition residue generated from petroleum raw materials contains a relatively low concentration of C of about 3 to 6%.
Contains 2H4. From these process waste casings, C2H
Separating, concentrating, and recovering gases that are effective as chemical raw materials P) such as 4 has always been a major technical challenge from the perspective of energy conservation.

Conventionally, C2H4 is separated from a gas source containing C2H4.
Methods for concentrating include the cryogenic Jff: method (distillation method). However, the deep cooling branch 1 method is based on a complex cooling and heat recovery system, and the operating temperature is low.
It is necessary to use expensive equipment materials, which increases construction costs. Furthermore, it has the disadvantage that the amount of power consumed increases as the temperature increases.

As an alternative to the cryogenic fractionation C11 method, which has such drawbacks, an absorption method that is fundamentally different in principle will be possible if an absorption liquid that selectively and efficiently absorbs C, H4 is developed. , driving =
Even with one stroke, the economical IS process becomes possible.

The object of the present invention is to reduce the concentration of C2 based on the above-mentioned viewpoints.
A new C2 with high C2H4 absorption capacity that can recover high concentration C2H4 from process exhaust gas containing H4.
The purpose of this invention is to provide an absorbent liquid for H.

The ethylene absorption liquid of the present invention for the purpose described in -1- is characterized in that it contains 1 ka chloride, trisdimethylsulfine oxide (hereinafter abbreviated as HMPA), and a solvent. It is in. The white monosolvent described in Section iii is preferably one consisting of one or more aromatic hydrocarbons such as toluene or xylene.

Hereinafter, the principle of the C2H4 separation/concentration process using the absorption liquid of the present invention will be explained with reference to the flow diagram of FIG.

The gas containing C2f is pretreated by the pretreatment device 1 as necessary, and passes through the raw material waste line 1. It enters the absorption tower 2, where C21-L is selectively absorbed.Absorption tower J, It
The residue is discharged into the atmosphere through the exhaust gas line 21 after the entrained components and the like are appropriately removed.

On the other hand, the liquid that has absorbed C21-L is sent from the absorption liquid line 31 through the heat exchanger 4 to the separation column 3, where it radiates C2H. The residue from the separation column 3 contains a high concentration of C2)L.
However, the entrained components are removed and the concentrated gas line 41
It is collected through the process and becomes product waste. The absorption liquid from which C2'H4 has been separated is returned to the absorption tower 2 through the circulation line 51 and used as a circulation group.

When the absorption liquid of the present invention is applied to an actual C2H4 separation/concentration process, the operating temperature and pressure can be changed depending on the C2H46 degree in the C2H4-containing gas, the contact time, the composition of the absorption liquid, etc. . Generally, when the absorption temperature is lowered, the amount of 02H4 absorbed increases, but a cooling device is required to lower the temperature, and the viscosity of the absorption liquid increases, sometimes causing the absorption liquid to solidify. On the other hand, if the absorption temperature is too high, the amount of C2H absorbed becomes small. In view of the above, the absorption temperature is generally preferably 10 to 50°C. Furthermore, the higher the absorption pressure, the greater the amount of C2H4 absorbed and the faster the absorption rate, but a gas compressor is required, and the equipment must also have a pressure-resistant structure, which increases construction costs. From this point of view, it is generally preferable that the absorption pressure is 0 to 20% in gauge pressure.C2I(
The absorption liquid that has absorbed
By contacting with a cow medium (e.g. water vapor, henocene vapor, etc.), and even with water (i) depending on the method of C2H4; nonos, 9 and j, C2
Dissipates I+4 and is regenerated. The above-mentioned dissipation operation may be performed in a similar manner or with i+t r>. released C2H4
Is it possible to collect σAU 'ni(+, C2FL dregs)?These dregs can be chemically synthesized by Kawahara!
! It is effectively used as a single gas.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In addition, the gas body immersion in the )ζ example is all the standard f (11 state (0'' C1I at+n ) C7) value.

Example 1 Volume 1.00 III/! Circle 1. In a J-shaped glass container,
Cupric chloride (hereinafter referred to as CuCe) 4.95g
(0.05 mol) was collected and placed in a nitrogen atmosphere F.
After adding 77.9 g (0.1 mol) of PA, ], and 37.1 g (0.4 mol) of toluene,
80% (volume %) of dregs of IL composition was continuously blown in at normal pressure, and the equilibrium absorption amount of C2■■4 under these conditions was determined. As a result, this absorption liquid had a concentration of 7.0% per ml. ! 5
m/! of C2H4 was absorbed.

When the C2H4-absorbed liquid obtained in Example 1 was heated to 100° C. and reduced to 50 m Hg, 7.5 ml of C2H4 was recovered per 1 ml of the absorbed liquid.

Example 2 Using the same cylindrical glass container as in Example 1, CuC19,
99 (0,1 mol) to HMPA 35.39 (0,2
mol) and toluene 1.9.09 (0.2 mol), gas was blown under the same conditions as in Example 1, and C
The equilibrium absorption amount of 2H4 was determined. As a result, this absorption liquid is l
Absorbed 15.0++J of C2H4 per ml.

Example 3 Collect 14.95 g (0.05 mol) of Cu C and add 17.99 (0.1 mol) HMPA and 42.49 (0.4 mol) xylene under a nitrogen atmosphere to prepare an absorption liquid. After preparing, the C2H4 equilibrium absorption amount was measured under the same conditions as in Example 1. As a result, even in this absorption liquid, 1
ml! 7.5 +++l of C2H4 was absorbed per hour.

Example 4 An absorption liquid of n11 composition, which was the same as that in Example 1, was newly prepared, and after adding 2 parts (% smoothness) of water thereto, it was allowed to stand at 30'C for 24 hours. Thereafter, the C2H4 absorption amount was measured under the same conditions as in Example 1. Part 1. 7.5 mA of C2H4 per m, e of absorption liquid
was absorbed, and it was found that the addition of water did not change its behavior at all.

As can be seen from the following explanation, the effect brought about by the C2H4 absorption 11k of the present invention is that C2H can be efficiently and stably separated and concentrated from various gas sources containing C21. Moreover, the development of an absorption liquid with a very high C2f(4 absorption capacity) has enabled C21-(4 minute 141
1. The concentration process can be satisfactorily completed.

[Brief explanation of the drawing]

FIG. 1 is a flow diagram showing the principle of the C2H4 separation/concentration process using the absorption liquid of the present invention. ■...Pretreatment device, 2...Absorption tower: 3...
Separation tower; 4...Heat exchanger; 11...Niji gas line 21-iJI' gas line. 31...Absorption liquid line: 41...IN Condensation gas line. 51...Circulation line. Representative Patent Attorney Junnosuke Chuwa

Claims (1)

[Scope of Claims] tl+ An ethylene e which is characterized by being made of cuprous tetrachloride, trisdimethylaminoposphine/oten/l-'' (also known as hexamethylposporazide), and an organic solvent. Yield liquid. +2+ The ethylene absorption liquid according to claim 1, wherein the solvent mentioned in rrrr is composed of one or more aromatic hydrocarbons such as toluene and xylene.